Ultrasensitive photoelectrochemical biosensor amplified by target induced assembly of cruciform DNA nanostructure for the detection of dibutyl phthalate

In this work, an ultra-sensitive signal quenched photoelectrochemical (PEC) aptasensor for dibutyl phthalate (DBP) detection was constructed by using a target induced cruciform DNA structure as signal amplifier and gC3N4/SnO2 composite as signal indicator. Impressively, the designed cruciform DNA structure shows high signal amplification efficiency due to the reduced reaction steric hindrance because of its mutually separated and repelled tails, multiple recognition domains, and a fixed direction for the sequential identification of the target. Therefore, the fabricated PEC biosensor demonstrated a low detection limit of 0.3 fM for DBP in a wide linear range of 1 fM to 1 nM. This work offered a novel nucleic acid signal amplification approach for enhancing the sensitivity of PEC sensing platforms for the detection of phthalates (PAEs)-based plasticizer, laying the foundation for its utilization in the determine of real environmental pollutants.

Automated summary

An ultra-sensitive signal quenched photoelectrochemical (PEC) aptasensor was constructed for dibutyl phthalate (DBP) detection, using a target-induced cruciform DNA structure as signal amplifier and gC3N4/SnO2 composite as signal indicator. The designed cruciform DNA structure exhibited high signal amplification efficiency due to reduced steric hindrance, and the fabricated PEC biosensor showed a low detection limit of 0.3 fM for DBP in a wide linear range of 1 fM to 1 nM. This work provided a novel nucleic acid signal amplification approach for enhancing the sensitivity of PEC sensing platforms for the detection of phthalates (PAEs)-based plasticizer.